Conventional rock bits which are employed for drilling wells and the like ordinarily employ two or three or more cone-shaped rolling cutters rotatably mounted on journals, the cutters having teeth or rock-crushing inserts on their conical surfaces. The cutters are so arranged as to roll, under considerable weight, upon the bottom surface of the hole being drilled as the well string to which the bit is attached is rotated. A fluid, such as air, is forced down the well string and is discharged through the bit to flush drill cuttings upwardly in the well bore. The cutters are mounted to the journals by interior, anti-friction bearings which are highly subject to wear and destruction if abrasive cuttings at the bottom of the well are allowed to penetrate between the journal and cutter and to contact the bearings or if there is a loss of lubrication from the bearings.
Various means have been employed to combat this problem. For example, compressed air may be fed to the interior of the bit to flush the anti-friction bearings of contamination. A seal may be employed at the exposed juncture of the journal and cutter to prevent migration of contamination inwardly to the bearings and to seal in lubricants. In the latter system, seals of varying materials and configurations have been employed, and exemplary of such seals are those shown in U.S. Pat. Nos. 3,096,835; 3,193,028; 3,381,968; 3,489,421; 3,397,928; 3,746,405 and 3,765,495.
It would be desirable to provide a seal between the cutter and journal of a rotary drill bit which would not only be highly effective in restraining the passage of contamination to interior anti-friction bearings, and retain lubricants such as greases or oils, but which would also lend itself to the ready assembly of the rolling cutter to the journal.